Flashbulb



SEN 23, 1952 J. POELMA ETAL 2,511,255

FLASHBULB Filed Feb. 17, 1949 IN V EN TORS AGEN.

Patented Sept. 23, 1952 FLASHBULB Jacob Poelma and Clamor August Lamberts, Eindhoven, Netherlands, assignors to Hartford vNational Bank and Trust :.Company, Hartford,

Conn., as trustee Application February 17, 194e, seran No'. 77,036 'j j VIn the Netherlands March `4., 1948 l c This inventionrelates to flashlamps the glass bulb of which is provided'with a gaseous llin and actinically reactive metal.

In order to ensure rapid combustion of the aotinically reactive metal, the same is distributed over the bulb space in the form-of thin wires, chips, strips or foil..` When use iswmade of chips or strips, thehandlingA Y thereof. .causes diiculty sincethe amount of .actinically reactive metal required inthe hash-lampisv small and suitable dosing is important. Actinically vreactive metal of drawn' wire having-avery 'small diameter is particularly suitable. Such metal wire Ymay be pneumatically ,provided in the Vdesired. division in the ibulb space.` As a rule; however, drawn wire havinga diameter-'of the orderiof magnitude smaller than 20 microns can be manufactured only with diiilculty,.sincethe manufacturing cost thereof is high. In certaincases such a manufacture is not practicable-atall.' 'l 1 Actinically reactive metal foil, however, can as a rule bemanufactured with great thinness. Arolling or platting operation permits of obtaining ,metal foil having a thickness of microns or even considerably thinner, for example a 5,8 Claims. (01.67731) thickness of from 0.5 to lmicron, but this is also using a foil oi'eonsiderably greater thickness as the starting material. Y l

Ai The present invention consists in` a flash-lamp', the bulb of which is. provided with a gaseous lling and actinically reactive metal in the form ofrstrips or wires. obtained by thatY metal vfoil having va thickness of 100 microns at the most, preferably athikness of 50 microns, isprovided with cuts atdistancesof 100 microns at the most and that the distance between the metal strip or'wires is locally increased by deformation;

Cuts may be providedi in foil materialwith the use of one or more rotary orv rectilinearly moving knives. Such cuts may be very close to one another, for example,with a spacing of from 5 Ito v10 microns, by the use-ofV a suitable mechanism for moving the foil. Since the resulting stripgfor wires are locallyV united, the possibility of handling the actinically reactive metal is `im-4 proved. Such unitedr metal parts may be trans-I ported in. a simple manner and vprovided in the bulb'of atlash lainpfwith the use .of a catcher, for' exampleapair of tweezers, which is operated normally nismi' or by a suitably. c'zonstructed mecha-V The local connection of the strips or wires obtained from foil material maybe realized-ln diierent ways. In .one form of flash-lamp'according to the invention, the metal strip or wires are united by means of one or more dams of actinically reactive metal foil, which dams subsist on the sides or somewhere between the sides of the metal foil when the cuts have-been provided. In a further form of constructionthe strips or wires are united pairwise at several points, which'points are gradually dispersed over the surface. lilxtending the extremities of actin; ica-ily reactive metal thus obtained ensures spatial distribution thereof such as is desired inthe bulb of a flash-lamp.

In order that thev invention may be clearly understood and readily carried into effect, it will now be described more fully by reference to the accompanying drawing wherein Figurel 1 is a perspective view of a length o an actinically reactive metal foil cut so as to provide metal strips in the manner'of the invention;

Figure 2 is va side view of a mechanism- `for cutting the metal foil. A length of foil being cut is shown in association with the mechanism;

Figure 3 is a plan View of the cutting head with blades thereon of the mechanism shown in Figure 2;

Figure 4 is a surface view of a length of foil showing the pattern obtained by using knives of different lengths with the cutting mechanism il-l lustrated in Figures 2 and 3;

Figure 5 is a surface view of another length of foil showing a different pattern obtained by using two knives cutting from opposite edges of the foil;

Figure 6 is a surface view of another length of foill illustrating still another pattern of cuts;

Figure '7 is a diagrammatic representation of a portion of the length of foil shown in Figure 6 and extended in the directionv of the arrows; while Figure 8 is an elevational View of a ash lamp incorporating foil in accordance with the present invention.

In Fig. 1, reference numeral I indicates actinically reactive metal obtained by providing metal foil with cuts 2 so as to obtain the metal strips or wires 3. 'I'he thickness d is 100 microns at the most. As a rule, however, according to circumstances, the thickness d will be smaller. The distance b between two cuts2 is also 100 microns atv the most,` but' this. dimension also willeenerally be".Jv s mal1`e`11i-1"Ifh'aA length; 'r`-,the

3 metal foil plays no part in the case under consideration.

The cuts 2 may be obtained in different ways. for example with the use of the mechanism shown diagrammatically in side-view and plan view in Figs. 2 and 3. The metal foil here bears the reference numeral II and is moved ,upwards over the desired distance b between two cuts by a mechanism (not shown). The metal foil II is supported by members provided on the table I2. In the table a cutting head I4 is provided on a spindle I3, the cutting head I4 carrying three knives I5, which alternately contact with the. metal foil Il, which in the meantime has. beenv moved upwards over the required width, thus cutting the metal foil. By av suitable arrange-- ment of the metal foil II with respect tothe" cutting head I4 it is ensured that in`this cutting operation a dam IB subsists, so that the-metal strips or wires produced` in cutting are united Wthone another. This can be clearly seen in Fig. 2. During cutting, the knives I5 cause the strips.- or wires to be slightly. bent over so that the actinically reactive metal acquires an entangled structure so as to obtain the desired distribution of the actinically reactive metal in the bulb space of aiiash-lamp according to the invention. This may befacilitated by giving not all the knives-I5 the same length or by varying the mutual cutting angle so that the strips or wires produced bycutting-arebent backwards to agreater or smaller extent. A comparable effect is-obtained by torsion of the strips.

It will-be vevident that thepattern of the cuts may be made in different ways. Fig. 4 shows the pattern which is obtained if not allthe knives of the cutting mechanism are ofthesaine length.- The figure shows that four cuts 22, 23, 24, 25 of decreasing length are provided in a metal foil 2|.

In Fig.'5, a metal foil 3| has provided-in it alternately two cuts 32, 33, which terminate at one edge of the foil, and twocuts 34, 35, which terminate at the other edge of the foil. This pattern-is particularly suitable to be manufactured with rectilinearly movable knives, in which event the cuts 32,l 33 are made by one knife and subsequently the cuts 34, 35 by another knife.- The desired spatical distribution is obtained by deformation, for example by extension between Vthe points 32 and 36. v Fig. 6 shows that the metal foil 4I has-provided in it-three cuts 42,- 43, 44 and beside them two cuts 45,v 46, which overlap the cuts l42,- 43, 44 in the-transverse direction. With this pattern itis possible, after -the said .cutsl in an actinically reactive-metal foil have beenv provided, to extend the foil in the longitudinal direction according to arrows 48 and 49. This results in the structure shown in Fig. '1, in which for the sake of simplicity the strips or wires of actinicallyreactivemetal areshown as lines. The dam may alternatively be provided centrally' between the edges of the metal foil owing to cutsbeing madewith a V-shaped knife. The distancebetween the strips or wires may be locally'increased by torsion of the dam.

In Figs. 1 to 7 the initial material used was a rectangular Vmetalfoil. It is alternatively. possible, however, to use metal foil of circular .or oval shape in which the` cuts extend, if desired, in theradial direction.

Fig. oshows a flash-lamp according to the invention.l The actinicallyreactive metal iillingindi'catedby the reference4 numeralsil and 52 is obtainedbyV providing metalfoil' with cuts as shown in Fig. 1 by means of the cutting mech- 4 anism shown in Figs. 2 and 3. The entangled structure of the strips or wires is clearly shown. The mounting operation of this filling causes no particular difficulties. The united metal parts may be provided in the bulb 53 by means of a pair of tweezers and;4 if desired, be attached to one of the internal parts of the-lamp, for example to either of the pole wires 54, 55. The extremities of the pole wires 54, 55, are connected by means of a filament on which the igniting mass 56 is provided. The pole wires 54 and 55 are connected tothe cap of the flash-lamp 51 and the central contact respectively.

What'we claim. is:

1. AA flash-lamp comprising a bulb, a filling gas in4 said bulb, .and. an actinically reactive metal in said bulb, said actinically reative metal comprising a "body of metal foil having a thickness of .not more than approximately 10D/u and a plurality of cuts therein spaced at distances between adjacent cuts of not more than approximatelyv 100/uto so separate a plurality of strips formed of said metal foil, said metal foil body being deformed whereby the distances between adjacent ones of -said-strips are increased.

2: A flash-lamp comprising a bulb, a filling gas in said bulb, and anactinically reactive metal insaid'bulb.saidiactinically reactive metal comprising a bodyv of metal foil having a thickness of not moreth'an approximately 10U/u and a plurality of cuts therein spaced at distances between adjacent cuts of -not more than approximately 1GO/lu, -said cuts extending from one isideA edge of said metal foil body to a region extendingadjacent thel opposite'side edge thereof to so separate a plurality of strips formed of-said metal foil which have common attachment to said region, said metal foil body being deformed 'wherebyA the distances between adjacent ones o'f said strips are increased..

3. A flash-lamp comprising a bulb. a filling gas .in 'said bulb, and an actinically reactive metal in said bulb, 'said actinically reactive metal comprisin'g a body ofl metal foil having a thickness of not more than approximately 10G/u' and a plurality 'ofcutstherein spaced atV distances between adjacent `cuts of not more than approxi-n mately lOO/u, said cuts being. discontinuous in and-dispersed over the surfaceof said metal foil body -to so separate a plurality of strips formed of saidv metal foil each of which said strips is connected to an adjacent one; at oneor more points along the lengths thereof, said metal foil body being deformed whereby thedistances between adjacent ones-of said strips are increased.

' 4. A Vflash-lamp comprisingA a bulb, a. filling gas in said bulb.. and an actinically reactive metal in said bulb,y said actinically reactive metal comprising a body of metal foil having athickf' nessof notmore4 than approximately lOO/u and a plurality ofv cuts-therein spaced at distances between adjacent cuts of not more than approximately 1D0/u,- partof: the number of said cuts extending from one side Vedgeof said metal foil body to a-region Aadjacent the opposite side edge thereof, while the remainder of said cuts extend from said opposite side edge to a region adjacent said one side edge to so separate a plurality of strips formed of said metal foil and which are attached at the extremities thereof to said regions, said metal foil body being deformed whereby the distances between adjacent ones of said stripsj'are increased.

5. A flash-lamp vcomprising a bulb, a filling gas in said bulb, and an actinically reactive metal adjacent the opposite side edge thereof to sov separate a plurality of strips formed of said metal foil which have common attachment to said region, said region of said metal foil body being torsionally deformed whereby the distances between adjacent ones of said strips are increased.

6. A ash-lamp comprising a bulb, a filling s l gas in said bulb. and an actinically reactive metal f in said bulb, said actinically reactive metal comprising a body of metal foil having a thickness of not more than approximately 10D/u and a plurality of cuts therein spaced at distances between adjacent cuts of not more than approximately 10G/u, part of the number of said cuts extending from one side edge of said metal foil body to a region adjacent the opposite side Y edge thereof, while the remainder of said cuts extend from said opposite side edge to a region 1 adjacent said one side edge to so separate a plurality of strips formed of said metal foil and which are attached at the extremities thereof to said regions, said metal foil body being deformed;

by extension whereby the distances between adjacent ones of said strips are increased.

7. A flash-lamp comprising a bulb. a lling Y gas in said bulb, and an actinically reactive metal in said bulb, said actinically reactive metal comprising a body of metal foil having a thickness f of not more than approximately 10U/u and a7'V44 plurality of cuts therein spaced at distances between adjacent cuts of not more than approximately 10G/u, said cuts being discontinuous in and dispersed over the surface of said metal foil body to so separate a plurality of strips formed of said metal foil each of which said strips is connected to an adjacent one at one or more points along the lengths thereof,V said metal foil body being deformed by extension wherebyl the distances between adjacent ones of said strips are increased. n

8. A dash-lamp comprising a bulb, a lling gas in said bulb, and an actinically reactive metal in said bulb, said actinically reactive metal comprising a body of metal foil having a thickness of not more than approximately 10D/u and a plurality of cuts of a predetermined number of different lengths therein spaced at distances between adjacent cuts of not more than approximately 10D/u, said cuts extending from one side edge of said metal foil body to a region extending adjacent the opposite side edge thereof to so separate a plurality of strips formed of said metal foil which have common attachment to said region, said metal foil body being deformed whereby the distances between adjacent ones of said strips are increased.

JACOB POELMA. CLAMOR AUGUST LAMBERTS.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 821,865 Dobbs et ai May 29, 1906 834,873 Curtis Oct. 30, 1906 884,714 Clark Apr. 14, 1908 1,996,621 Kurlander Apr. 2, 1935 

